A poke-through device or simply a “poke-through” is a common device that enables power, data or other cabling to pass through a hole in a floor of a structure, generally a concrete floor. A thermal barrier in the form of a fire and/or smoke retardant element, particularly intumescent material, is incorporated within the poke-through to seal the floor opening in the event of a fire. This helps prevent a fire or the smoke from spreading from one floor to the next.
Contemporary poke-throughs provide access between an upper floor and an immediately adjacent lower floor. The poke-through assembly is usually installed with a cover which serves as a cap or lid for the hole. Also, the poke-through generally includes an upper frame or basket designed to create an easily accessible cavity or recess at the surface of the upper floor. Alternatively, such frames or baskets can be used to hold power and/or data receptacles therein. The upper frame is generally metallic and is in direct contact with a cover plate or the upper flooring itself. A lower end of the contemporary poke-through is connected to a junction box accessible to an adjacent lower floor. Intumescent material is generally used between the upper basket and the lower end. Also, the upper and lower portions of the poke-through are secured with a number of metallic bolts, screws or other fasteners that pass through the intervening intumescent material. However, the intumescent material does not provide a stable support structure, especially when heated substantially. Thus, the fasteners provide a more durable coupling for the upper and lower portions of the poke-through.
While the intumescent material acts well as a thermal barrier, the metallic fasteners pass through the thermal barrier and conduct heat to the upper portions of the poke-through. As the heads of the fasteners are generally in direct contact with the metallic upper basket, portions of the adjacent upper flooring can overheat from the conductive heat transfer.
There is therefore a need for a poke-through device that provides improved heat isolation features. Such heat isolation features preferably minimize and/or reduce conductive heat transfer within the poke-through that bypasses the traditional thermal barrier. Such improved heat isolation features must be inexpensive, manufactured easily and quickly installed. Additionally, it would be beneficial if the improved features could be retrofit into existing poke-throughs without replacing the entire assembly.